The present invention relates to an arrangement in a distributed system, for example a control, monitoring and/or communication system, which comprises module units, what are known as nodes, which are locally arranged or spread out and perform one or more function(s). The system comprises one or more unit(s) at a higher level than the module units and determining system functioning, and one or more connection(s) connecting said units. The higher-level units determining system functioning can be connected or connectable continuously or on different occasions and also on the same or different occasions with regard to the module unit(s). Each module unit can be connected to the connection concerned via a connection facility, more popularly known as a connection point or connection points. In this context, the units are arranged so as to work according to fixed rules or a fixed rule system. One or more connection(s) can then be used and consist of a multi-wire connection, for example a two-wire connection. The connection can consist entirely or partly of a wire connection, a wireless connection or an optical connection. A connection of the IR type (infrared connection) is also possible. Each wireless connection can be or comprise capacitive/inductive coupling at relatively short distances as well as electromagnetic fields (radio signals) which are transmitted at short or long distances.
The transmissions described above can themselves be regarded as electromagnetic fields, and radio technology can be regarded as technically separate from transformers and near-field transmissions. Light too can be described as an electromagnetic field.
In this context, each module unit can be of the kind which is connected to the bus connection concerned via an establishment of contact, which comprises on the one hand a first contact unit with a first set of contact means which are connected or connectable to the module unit in question and second and third contact means which are connected or connectable to said bus connection. The establishment of contact can moreover comprise a second contact unit which can interact with the first contact unit and has fourth contact means which can interact with the first, second and third contact means in order to make it possible to connect the module unit to the bus connection. The invention also relates to a contact unit of said kind. The invention also relates to a method of producing the system in question for control, monitoring and/or communication.
This kind of system, what are known as distributed systems, can consist of, for example, CAN (Controller Area Network) systems of kinds known per se, which can be of standardized type (ISO). In this respect, mention may be made of field bus systems of the Profibus, Fieldbus Foundation, Control Net, Device Net, CAN-KINGDOM, RedCAN, Ethernet types etc. Reference can therefore be made to different protocol types of said kind with different bit speeds and, in this context, bit speeds in the order of 0.01-500 Mbit/s may be mentioned. Reference can also be made to more striking speed protocols which work in, for example, the 2.45 GHz band (Blue-Tooth). Reference is also made to CAN and USB/IEEE 1394. With regard to construction, functions etc., reference is made to inter alia patents obtained by the same applicant as is making this patent application: U.S. Pat. Nos. 5,371,859, 5,383,116, 5,446,846 and 5,696,911; WO 97/31454, WO 97/40429; and patent applications U.S. Ser. No. 08/954,560 (SE 9402683-3), U.S. Ser. No. 09/101 748 (SE 9600652-3), and the novelty references indicated in these patents and patent applications.
In the production of distributed systems of said kind, there is a need for it to be possible to individually adapt or customize the system to requirements. Today, the market is characterized by a large number of different systems which each meet the various requirements concerned, but where the components and parts of a system cannot be used in other systems or where problems arise when certain components or parts are replaced with components which function differently or are more modern and effective unless a large number of other components are replaced or the overall performance and capacity of the system are restricted. There is therefore a need for it to be possible to propose systems which, in the manufactured state, can be subjected to modifications without major rebuilding and reconstruction being necessary and without the specifications of requirements having to be changed for the system as such. It is also important for it to be possible to break the system construction down into the system functions of which the system is composed and which are themselves very distinct. For example, it is important for it to be possible for the design in terms of systems engineering to be carried out essentially independently of the module unit application and for the system construction to be organized primarily by the system experts without them having to go into the construction and functions of the module unit and make special demands of these on account of system construction and system functioning. Conversely, it is likewise important for it to be possible for the local functions which the module units are to be capable of performing to be carried out and subjected to requirements without this involving demands having to be made for system functioning to be changed on account of modified requirements or specific peculiarities of module functioning, or system functioning and module unit functioning having to be limited or effected in a special way in relation to applicable (for example standardized) basic functions and basic requirements/rule systems. The present invention aims to solve all or some of these problems by making possible construction of the system and the module units which is in principle modular and where it is not necessary to begin construction by starting out from the functions of the module units and then adapting the rest of the system structure to these. Instead, it is to be possible from the outset to establish the system type which is considered suitable, after which the construction and connections of the module units are arranged so that they will be capable of working with the system thus selected. The object of the invention is to solve this problem also.
A desire therefore exists for it to be possible to structure and simplify the construction and to bring down costs in comparison with conventional arrangements and methods. The function module itself does not have to be designed for a specific system, and vice versa. The module unit is to be capable of being designed with its local task(s) and is also to be compatible in relation to the requirements of systems engineering. The invention solves this problem as well.
In using existing systems in order to solve certain problems which arise, it has been found that finding a solution to the problem has been relatively complicated in practice and that a need exists for simplification in this respect. The present invention solves this problem by proposing adaptivity to other system(s) with a better capacity to solve the problem in question without it being necessary to this end to deviate from the basic system or the system type as such. A need may also arise for it to be possible to double-utilize the connection system so that, for example, it can perform a basic function at the same time as it is possible, in a time-slot arrangement or via a filter arrangement, to transmit protocol functions which work at a different bit speed, for example a considerably higher bit speed.
There may consequently be a need for it to be possible to transmit software or other downloadable functions to the module unit(s) simultaneously with or alternatively to basic functions performed with the downloading or transmission in question. The invention solves this problem as well.
A need also exists for a simple and reliable possibility for performing test and simulation functions during system construction and/or in system functioning. There is also a desire for it to be possible to increase the supply of module units which can be sold separately on the market in relation to the rest of the system, and for the system to be capable of using a significant number of systems and selected protocol types. As far as the module unit is concerned, the use of what is known as a gateway or individual control and monitoring of the module unit on the part of the system are to be possible. The connection and/or the point-point connection should also be capable of working by wire, wirelessly, by optical means, by IR or a combination or combinations thereof (see also the concepts referred to above). In the case of connection of systems with high bit speeds, it is to be possible for transmission with a great bandwidth to be effected. The module units are to be capable of belonging to, for example, CAN and USB, the module units being connected to the system setup concerned, for example of the CAN type. The USB module is then made with adaptations to the CAN system while the CAN module can work without said adaptation to the CAN system etc. The invention also solves all or some of this problem.